ICD-10 Code F51.02 – Adjustment insomnia (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code F51.02 – Adjustment insomnia
What it is
Adjustment insomnia is trouble falling asleep, staying asleep, or waking too early that begins after an identifiable stressor or life change. Use this code when the insomnia is linked to an adjustment reaction rather than another sleep disorder.
Clinical signs
Typical findings include sleep disturbance that starts soon after a stressful event, with resulting daytime fatigue, irritability, or poor concentration. Clinical features vary; refer to documentation.
When to use this code
Use F51.02 when the record documents insomnia associated with an adjustment problem, such as relocation, job change, relationship stress, or another clear life stressor. It is appropriate when the provider identifies adjustment insomnia as the diagnosis and does not document a different primary sleep disorder.
Do not use for
Do not use this code for insomnia caused by substances, medications, or a medical condition. If the chart describes another specific insomnia diagnosis or the cause is unclear, check documentation.
Coding tip
Code the documented adjustment-related insomnia only when the provider clearly links the sleep problem to the stressor.